The effect of haematocrit on cerebral perfusion and clinical status following carotid occlusion in the gerbil.

The effect of haematocrit on the sequelae of carotid occlusion has been studied in the gerbil stroke model. In 72 animals one carotid artery was clipped. After 30 minutes, the area of cerebral hemisphere filling with a carbon suspension administered intravenously was measured on coronal brain slices and related to the haematocrit. Exchange transfusion of autologous packed red blood cells or plasma produced a haematocrit range of 26% to 59%. At high haematocrit a larger area of non perfusion was more commonly encountered, and the anterior cerebral artery territory was more frequently affected along with that of the middle cerebral. Fifty-seven animals had temporary occlusion of both carotid arteries. Survival was adversely affected at high haematocrit. The role of haematocrit in affecting the pathophysiology of cerebral ischaemia is discussed.